Column: Blend of good, bad is box office in Chelsea's Costa

When football historians tell the story of the hurricane that battered England in the form of Chelsea forward Diego Costa, they might pinpoint this week as the moment when admiration started to sour into disdain.

By stamping on the ankle of Liverpool's Emre Can, Costa took ownership of the Premier League's unofficial title of No. 1 Bad Boy that Luis Suarez vacated when he started afresh with Barcelona this season. As Suarez showed in three-plus years of thick and thin at Liverpool, when he was both adored and pilloried, often rightly so, a bad reputation can become a heavy load to bear, for both a player and his team.

Life both on and off the pitch will change — by how much will depend partly on his behavior going forward — for Costa when he returns in two weeks from the three-match ban handed down Friday that will keep the Premier League top scorer from one of the pivotal games this season: Chelsea against title rival Manchester City on Saturday.

Having seen how the Brazil-born, street-hardened striker pulled the wool over the eyes of their colleague Michael Oliver, who missed the stamp that cameras caught, referees will be even more acutely aware that Costa needs watching.

More than ever, the scrutiny will be not on the beauty of his football, but on his ugly tricks and brittle temperament, too. To try to make his self-destructive impulses boil again, opposing fans and players can be counted on to give Costa an even more torrid time. The "elephant man" chants directed at Costa by Liverpool fans could give way to spikier taunts. Opposing players will be encouraged and prepared to give as rough as they get from the uncompromising, crafty and physical Spain international.

And rabid voices in the sports media, already calling him "Dirty Diego" and "monster," will be ready to slobber fresh demonization and gleefully dismantle another idol they helped create the next time Costa's slow-burning aggression bubbles over.

As it surely will.

Treading Chelsea's King's Road can't wash out the Brazilian streets that were Costa's school of football to his mid-teens, shaping him into the slippery bruiser with quick feet whose combination of rough and smooth, of brutishness and skill, of instinct and intelligence, so appeals to Jose Mourinho, the Chelsea manager with many of the same qualities. As with some dogs and their owners, they are starting to resemble each other. Bark, bite and then deal with the consequences.

"There is a downside of never having a formal education," Costa said in a BT Sport television interview last year. "There's also advantages, though. You learn about the tricks of the game quicker and you become smarter by playing on the streets against older guys."

Stomping on Can wasn't smart. But it was in keeping with Costa's habit of making clear early in games that he is a force to be reckoned with. Can was one of Liverpool's best defensive players in the 10 opening minutes of the second leg of the League Cup semifinal on Tuesday. Only coincidence, then, that it was his right ankle Costa trod on? Mourinho said this was an accident. But if it looks like a stamp, aches like a stamp, and leaves a player writhing like a stamp, then it probably is a stamp. This much is certain: Costa made no deliberate effort not to land on Can.

Manchester City manager Manuel Pellegrini expressed hope that the three-match ban for violent conduct might help change Costa.

But not, hopefully, change him too much. Costa's rough edges, the blend of bad and good, make him box office. Will he score? Start a fight? Or both? The tingle of anticipating what Costa might do next is making him the most entertaining Premier League player this season. Even as he torments them with goals and doggedness, fans and players not wearing Chelsea blue would give hind teeth to have Costa on their team.

That said, the line between being edgy and a boor is a thin one. At Liverpool, a ban for racial abuse and his penchant for biting opponents made Suarez more trouble than he was worth. The club misses his goals but its image is better with him gone.

Costa and Chelsea need to dial back before he also gets to that point.